WHY FLOATATION BODYSUITS ARE UNFAIR

Brent S. Rushall, Ph.D.,R.Psy. [03/272001]

The swimming bodysuits, from "Jammers" to Adidas' "Thorpe-suits," worn mostly in major competitions, are floatation devices. The suits trap air in relatively thick fabrics, in pockets under the suits, and even resist wetting through the application of surface coatings (e.g., Adidas' Teflon coating). When these suits are new, the surface tension of the suits also causes bubbles to adhere strongly to the fabrics (see Figure 1). When a large amount of fabric is worn, in comparison to tight brief "traditional" suits, the volume of the floatation assistance is increased markedly.

Figure 1. Red lines point to some of the air bubbles adhering to the fabric surface of a Speedo Fastskin suit. Trapped air appears as gray specks in the fabric. [Picture courtesy of the Counsilman Center for the Science of Swimming, Indiana University.]

As suits become increasingly available, swimmers report almost universally that bodysuits make them feel "lighter," they "float higher," and particularly among males, they assist in "holding the legs up." Some coaches report they can "see the difference" when bodysuits are worn, particularly in males where the feet are carried closer to the surface. Scientists, able to compare bodysuits to traditional suits for affect on specific gravity in underwater weighing tanks, report a floatation effect for bodysuits (i.e., a swimmer's specific gravity is less when a bodysuit is worn).

Floatation is transitory. Eventually, bodysuits do absorb water, which displaces some trapped air. As bodysuits wear, fabrics lose resiliency and/or coatings wear-off, reducing the time they remain fully effective as "floaters."

That bodysuits, their fabrics and coatings, assist in floatation in a manner similar to a thin wetsuit, is indisputable.

What should be of concern to anyone who cares about the sport of swimming and the conduct of fair competitions, is that these suits are even allowed.

Whether every swimmer has a bodysuit in a competition is immaterial (no pun intended). What should be of concern is the amount of floatation a bodysuit's covering provides relative to the size of the swimmer. The greater the amount of floatation to size ratio, the greater will be the degree of effect (i.e., assistance). Some examples that illustrate this subtle point that will affect swimming race outcomes are as follows.

  1. Thin swimmers have smaller body surface areas than do fuller swimmers. Thin swimmers have a higher percentage of bone and muscle mass, the heavy parts of the body structure, in their total body mass than do "thicker" swimmers. They sink lower in the water because they are denser. The proportion of surface area to height in thin swimmers is smaller than for "larger" swimmers. Thus, the amount of bodysuit floatation for a thin swimmer will be less than the amount for a stockier swimmer because, for the latter, the amount of fabric to swimmer height will be proportionally larger. The larger a swimmer, the greater will be the body surface area and the amount of bodysuit fabric needed to cover it. Those swimmers will derive a greater floatation benefit. Coaches have verified this reasoning by noting that thin swimmers do not seem to get as much benefit from bodysuits as do thicker swimmers.

  2. The style of bodysuit worn will affect performance differentially. Bodysuits that have upper body and full leg components will provide more floatation for crawl and butterfly stroke swimmers. The larger floatation volume of the suit provides more assistance. Full bodysuits will float swimmers more than will abbreviated bodysuits, such as Jammers. If the size of suit worn is dictated by economics (i.e., what a swimmer can afford), then a richer athlete gains an advantage by being able to purchase a larger and more costly suit. Thus, the economics of the sport to a certain extent will influence the outcomes of races.

  3. As has been described elsewhere (Rushall, 2000), the tension and rigidity of tight-fitting bodysuits can assist some swimmers with technique flaws. When loose/swaying hips are a problem, bodysuits reduce the effect of that fault, enhancing the economy of stroking. On the other hand, it is the stiffness that resides in bodysuits that makes them hindrances for strokes such as breaststroke and backstroke, where the ranges of joint movements, particularly in the legs and hips, are large.

For swimmers, particularly males, who have "sinking feet" due to a relatively large distance between the center of buoyancy and center of mass, added floatation below the center of mass produced by waist-to-knees or waist-to-ankles bodysuits, improves performance. The effect "lifts" the lower body higher; improving streamline and reducing the effort and size of kick needed to complete the streamline. Energy savings from that assistance can be applied to increase the level of beneficial effort in a race.

These are two examples of differential technical assistance derived from bodysuits. Others undoubtedly occur. When some swimmers have particular flaws in technique, those flaws should affect competition outcomes, better swimmers being rewarded for better swimming. However, in special circumstances, bodysuits will bring poorer swimmers closer to better swimmers, an assistance that will pervert the fairness of competitions.

The three features cited above are but a few bodysuit effects that are specific to individuals. Bodysuits do not produce a "universal" benefit. They cause the fairness of swimming competitions to be violated. It is false to believe that if all swimmers in competitions wear bodysuits, fair competitions will ensue.

Any competitor beaten by a swimmer in a bodysuit is justified in wondering how much of an advantage was gained by the swimmer simply through using the suit. The wearing of bodysuits in races is antithetical to the notion of fair competition, which is "may the best person win."

Reference

Rushall, B. S. (September, 2000). How bodysuits might help some swimmers. ISBS Swimming: Opinions, Ideas and Hypotheses in the Making [https://www.education.ed.ac.uk/swim/br.html].

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